In general, LED lamps are used for back lightings which are mounted inside dashboards or switches, or used for lightings which are mounted inside or outside a vehicle like incandescent lamps and fluorescent lamps in order to help a user to distinguish things, such as courtesy lights of vehicles, license plate lamps for distinguishing license plates at night, trunk lamps, wing mirror lamps, fender lamps, winker lamps, and so on. Now, such conventional LED lamps will be described.
First, the conventional LED lamps use filament lamps of various shapes, but has several disadvantages in that they lamps have very short lifespan (about 100 hours to 1,000 hours), generate lots of heat so that a user may get scalded when grasping it with hands, consume lots of power (5 Watt to 30 Watt), and are darker than LED lights.
Second, the conventional LED lamps use high-intensity LEDs on a metal PCB, but have several disadvantages in that they are more expensive than other existing products because a metal PCB is applied only to resistance and LEDs which generate lots of heat and a general PCB is applied to the remaining circuit parts due to a high price of the metal PCB and in that the entire set of the LED lamp must be changed at the time of after service because they need separate controllers.
Therefore, in order to solve the above-mentioned problems, the LED lamp was manufactured into a socket type using the general PCB. However, due to a lack of thermal control technology, even though the quantity of light which corresponds to 40 percent of characteristics of the mounted LED is just used, namely, a rated current of the LED is 350 mA but only 150 mA is used, the LED lamp also needs radiation of heat using a reflector due to generation of high heat.